Parasiticidal oil



Patented Apr. 2, 1929.

UNITED STATES PATENT QOFFICE.

WILLIAM HUNTER VOLCK, or wATsoNvILnE, CALHORNIA, ASSIGNOR 'ro cALIronNIA SPRAY-CHEMICAL COMPANY, or WA'rsoNvnLE, CALIFORNIA, A CORPORATION or CALIFORNIA. v

' No Drawing.

lVhat may be designated as phytonomic oils are certain classes of oils by means of which plant'lit'e can safely be regulated and protected from the depressingand frequently destructive action of parasites, such as incrude petroleum commonly known as lubrieating stock of suitable viscosity and subjecting it to treatment with fuming sulfuric acid of a strength known as 105%.o1eum until it is sufliciently sulfonated to produce a good white oil, thereuponneutralizing-by washingwith caustic soda, steam distilling the washed oil and finally filtering it through fullers earth or the like. As crude petroleum stocks and consequently the lubricating stocks, differ it is impossible to specify exactly what portion to select for eachof the above oils; more particularly sincethe above treatment modifies the gravity and viscosity of the stock usedto some extent and some stock requires repeated treatment with oleum or caustic soda or both. Experience,

' however, enables the operator on a suitable stock to so select the portion taken for making i Crystal Markol I Wyrol Nu ol omnite Asto obtain sp.g .835-.840' .880.885 tee-ass sm-.s70 Saybolt viscosity 100 70-75 120-130 210220 100-110 and still repeat some or all the above treatments until the product is practically waterpetroleum taste and odor.- Methods of similarly refining the suitable stocks derived from other and different crude petroleums are well known tothose engaged in the in dustry. I

It has hitherto been supposed'that the best obtainable oils of this classow ed' their phy- PAnAsITIcmAI. OIL.

Application filed September 8, 1926. Serial No..13l4,829.

I have now discovered that exposure to air, high temperature, light, or certain rays, or the like, or exposure to certain combinatrons of these agents, is capable of so modifying some phytonomic oils (or at leastcertainconstituents thereof) that they become actively phytocidal and I have in many cases been able to reproduce these changes in the laboratory and within the period of laboratory experiment. For example, if a sample of any of the present white oils of commerce is exposed-to the air in an open vessel and held at a temperature of 100 (1., oxidation products will appear in 24 to 48 hours, according to the actual temperature and the specific nature of the sample.

I believe that these oxidation products are largely napthenic acids in various stages'of synthesis by oxidation from certaincomponents of the oil. The completely formed napthenic acids are similar to the fatty acids cidity in animal and vegetable oils, the difference being that rancidity in animal and vegetable oils is due to the release of existing fatty acids and possibly to their further alteration-whilerancidity in a white oil I believe depends on the production of acids not previously existing. With this reservation the deterioration of white oils by oxidation might be spoken of as the development of rancidity.

. The importance. of this rancidity in phytonomic oils is due to the fact that the napthenic acids or other degeneration products are very toxic to plant tissuewhereas the original white oil as hitherto used by meis for practical purposes free from toxicity to plant tissue and might be applied freely in the control of insects and other plant parasites when it remained substantially unchanged. The rancidity' which develops in white oils at about C. also takes place at lower temperatures but much more slowly.

Under ordinary laboratory cOnditiOnQ-itmay.

require several months for perceptible ranci llity to develop in a given sample of white 01 I believe the rate of oxidation or other degeneration is greatly influenced by the extent of the surface exposedto the air, as well as by the sunlight increasing the rapidity of the development of rancidity in oils. It is Well known that nascent oxygen is much more active than the oxygen of the air.

. It is certainly a fact that a very thin oil film spread over the surface of a growing plant and partly penetrating the intercellular spaces of the leaves, is in a condition favoring rapid degeneration of the oil, and if at the same time the temperature rises abnormally high (38 C. or 100 F., or above), this tendency may be so enhanced as to bring about a condition of toxicity which is detrimental to the plant tissue following the application of the spray which in itself was harmless.

During the past four years very extended experience with the use of phytonomic oils applied to a great variety of growing plants and under practically all weather conditions, has shown that in the great majority of cases the use of 'phytonomic oils has not been attended by any injuryto the plants sprayed. In a small percentage of cases, however, princip'ally where the application was made during unusually hot weather, unfa vorable reactions have developed from oils elesewhere shown to be harmless and occasionally developed a sufficient extent to attract general notice.

The above-mentioned phenomena led me to make a very careful investigation of the conditions surrounding the oxidation of socalled white oils. As a result I have discovered that ordinary white oils are subject to rancidity and may become more or less phytocidal. I have further discovered that white oils need not necessarily develop ra-ncidity at 100 (3., and have perfected methods whereby I can prepare substantially pure saturated oils which are also substantially non-oxidizablc so that oils which are practically stable phytonomic oils may be manufactured.

I. The white oils hitherto known to the art and obtainable under various trade names, such as \Vyrol, Crystal 'oronite, Marcol, white oil, Amaline, etc., may be used as a source of stable phytonomic oils. They are found to consist of two general classes of hydrocarbons; one much more readily oxidizable than the other. These groups grade into each other in a more or less continuous series and are therefore difficult to separate definitely. A practically definite separation of the less oxidizable group can, however, be

made by oxidizing the more oxidizable comonents in a given sample and then removmg the oxidation products by treatment with sulphuric acid, washing, neutralizing the un- Examples of the efiect of .this oxidation treatment on such raw materials are as follows:

1a. A commercial white oil prepared from California base by treatment with sulfurous acid and known as Volck stock, having.

a specific gravit of .865 and Saybolt viscosity at 100 F. of a out 100 and which by standard test for saturation (treatment with C. P. Conc. H 30 shows 100% saturated hydrocarbons, may be treated by this air oxidation process for 284 hours at a temperature ranging from 90 C. up to 110 C. The volume of theoil is found to have. decreased about 12% while the sp. g. has risen to .917.

\Vhen the resulting nnxture is treated avitlr concentrated sulfuric acid, .washedwith water, neutralized with caustic soda and finally filtered through fullers earth, it is found that only 66 70 of the original amount of oil is left while 34% has shown itself capable of slow oxidation and removal. The remaining 66% however is no longer suscepti 'le' to slow oxi dation as was the original w lite oil but is now a stable phytonomic oil.

1?). Another white oil prepared by the Standard Oil Company of New Jersey and sold under the name of Markol, having a sp. gof .843 and a Saybolt viscosity of about 76 at 100 F. tested'100% saturated hydrocarbons. lVhen air oxidized for 284 hours over a temperature range from to C. the volume loss was about 13% while the spe cifie gravity rose to .894. Again after cleaning up as above described the loss proved to be about 3-l% butthe remaining 663.- showed vastly greater stability against slow oxidation and was much more stable under atmospheric conditions and safe to a pply to plants in hot dry sunshine.

'10. A sample of white Amaline" from L. Sonneborn Sons, Inc.. New York city. was similarly examined and processed. The original white oil was 1009;, saturated hydrocarbons and had a gravity of about .826. Its

Saybolt number was not taken. After processiug as above for 161 hours over a temperature range of C. to C. it showed 13% loss in volume and its sp. g. rose to .872.

After cleaniLg up as above described 363;.

was found to have been lost but the remaining 64% .was of good phytonomic quality and was quite stable. i a

This oxidation indicates the .pres'enceof about 35% of unstable materials in these oils,

lie

connection,that the resulting oil does not differ materially in gravity or viscosity from the original sample although there may have been as much as twenty-five per cent loss by evaporation during the oxidation process.

Such a method of production is expensive and needlessly complicated.

II. Another method of separation is distillat-ion under suitable conditions, for example,

as follows: If a sample of commercial white oil is placed in a still and held at a temperature not materially exceeding 300 C. and a rapid stream of mixed gases, consisting of hydrogen or illuminating (water) gas and sulphur dioxide, is passed through the sample and thence through a condenser, a. separation of oxidizable and relatively non-oxidizable components is effected. The residue in the still becomes progressively non-oxidizable until 60 to 70 per cent of the original sample has been distilled over. The residue may be as much as 5 times as resistant to oxidation .as the original sample. The still residue is slightly cracked and can be subjected to; a sulphuric acid treatment to restore it to its original pure white oil condition. In this manner also stable phytonomic oils may be produced, but at considerableexpense.

In this connection it was noted that the still residue product differs from the oxidation method product, in that .it is more viscous, heavier and less volatile than the original sample and that the oxidizable groups in a white oil appear to behave quite differently from the unsaturated groups in lubricating distillates, in that the-latter are not generally separableby distillation. having thus determined the existence of relatively non-oxidizing groups in the present commercial white oils. I proceeded to examine the lubricating distillate from which these oils are derived.

I discovered that these (listillates did not exhibit the same oxidation phenomena as the white. oilsg inother words, the lubricating distillates are must less oxldlzable than the white oils produced from them by present methods. I further.discovered that the purtial removal of unsaturated hydrocarbons by treatment with sulphuric acid to produce oils ranging from 80 per cent to 97 per cent saturated might be so carried out that it resulted in products which were practically non-oxidizable at 100 C., andfinally that further,

treatment with sulphuric acid to produce pure white oils could be so adjusted as not to destroy this high resistance to oxidation. I thus demonstrated the hitherto unknown fact that the essential hydrocarbons of the white Therefore, after oils as they naturally exist in the lubricating distillates are often highly resistant to oxidation, but that the present commercial methods of purifying them actually produce oxidizable substances or groups which were not present in the distillates and which are synthetic rather than natural components of the white oils. Thus I discovereda more direct, simple and economical method of making stable phytonomic oils. I discovered that high temperatures tended to produce such oxidizable'groups and that the use of excess fuming sulphuric acid invariably produced them.. Further I discovered that in this method'for the preparation of non-oxidiza- 'ble white oils, the removal of the final two or three per cent. of unsaturated hydrocarbons is the most critical point in the treatment of the lubricating distillates. It is just at this point that, in the standard factory process of making white oils, it is customary to use an excess of fuming sulphuric acid which accounts for the'presence of readily oxidizable components in the white oils. Thus I have discovered the following processes for producing'more economically the stable phytonomic oils.

III. The lubricating distillate is,vigorous- I lyjagitated with sulfur oxide in the form of ordinary sulphuric acid preferably not exceeding 1.84 specific gravity for a period not less than one hour at-a temperature regulated preferably not to exceed 50 0., after whichthe sulphonic acids and sulphuric acids are allowed to separate by gravity, and the white oil is removed from the top for further purification by neutralization, washing, and fil tration through fullers earth. The amount of sulphuric acid required is from 3 to 5 times the volume of lubricating distillate if the reaction is to be completed in one operation. If, however, the operation'isconducted in stages,using only a portion of the acid at a time, the relative quantity of acid may be may require, for example, from 250 to 350 parts by weight. of fuming acid to 500 parts by weight of the distillate. 'lemperature control (such thatthe temperature will preferably not rise above 50 C.) is very essential. As the reaction is-str'ongly exothermic,-it is practically desirable to conduct the operation instages, when large bodies of distillate are used. In practice with the fuming acid reaction it is best to stop just short of saturated (98% to 99%) and to complete the operation with an excess of 1.84 sp. g. acid.

covery of excess acid are the same as for'the preceding method.

V. The removal of the great bulk of unsaturated hydrocarbons may be accomplished by another sulfur oxide in the form of liquid SO by a solution method process, after which sulphuric oxide may be used, as above indicated, to complete the purification. As heavy lubricating distillates are not readily work able particularly at 0 0., it is advisable either to operate under pressure or to dilute with kerosene or other volatile distillate, or both. With kerosene, for example, equal parts of the diluent and lubricating stock may be used. This allows ready separation of the liquid S0 and its dissolved unsaturates from the oil. After the washing with liquid sulphur dioxide is complete, the kerosene or other light distillate may be removed, either by vacuum distillation or by gas-stream still, using, for example, a mixture of illuminating gas (water gas) and sulphur dioxide. When the kerosene or light distillate has been removed from the mixture'the latter is treated with ordinary sulphuric acid and finally neutralized, washed, and filtered through fullers earth to produce stable phytonomic oil. The sulphur dioxide process has the obvious .advanta e over the sulphuric acid process, in that there appears to be less possibility of altering the chemical nature of any of the components naturally occurring in the lubricating distillate, into components of the white oil, which are unduly susceptible to oxidation or other objectionable degeneration.

As specific illustrations of the results obtained by such processes of treatment I may cite the following:

Heavy lubricating distillate 21 B. (western or asphaltic base type) diluted with an equal volume of k'erosen'e oil was treated with 20% fuming sulphuric acid until 99% saturated. The kerosene was removed by distillation at 200 C. in the mixed-gas-stream still, the residue treated with 1.84 specific gravity sulphuric acid, washed with alcohol, neutralized and filtered through fullers earth. The product so derived tested as folows:

Saturation 100% white oil, gravity 30 B. Volume taken for oxidation test 250 cc. Weight 219.2. grams.

After oxidation for 110 C.

Volume 236 cc., Weight 210.5 grams. Sulphonation test 100% white oil or no oxidation.

Standard Oil Company of California 100 pale stock 24 B. (a partly refined lubricating distillate with a saturation value'of 62%) was treated with excess 1.84 specific gravity sulphuric acid until 100% saturated. Washed,

284 hrs. at 90 to neutralized and filtered through fullers earth, the product showed:

Saturation value 100% white oil, gravity of sample 30 B.

Volume taken for oxidation test 250 00.,

example, combined distillation and blowing with streams of air have been applied to convert a crude or partially unsaturated oil with practical completeness into alcohols, aldehydes, ketones, and acids, for the purpose of producing these bodies. Again oils have been distilled in the presence of inert gases, such as steam, to reduce'the partial pressure of their vapors and facilitate the complete distillation with a minimum of cracking. And again oils have been treated with various strengths of sulphuric acid and atvarious temperatures according to the convenience of the acid supply and the local water and weather conditions, for the purpose of removing unsaturated bodies and other impurities and making white oils. But this has been done without observation of, or interest in, the amountofoxidizable components therein, and without any attempt to avoid the production of such bodies. Finally sulphur dioxide gas or liquid has been applied to oils for the purpose of bleaching, or sterilizing, or partially cooling and reducing the oils, but with no recognition of the peculiar function or advantage I have discovered. So far as I am aware, no one has ever applied any of these treatments to the production of stable phytonomic oils, or specially applied them to produce oils for insecticidal pur-- poses or for any other purpose in which the poison developing action of the components thus avoided or eliminated played any rdle.

For making stable phytonomic oils I prefer one of the above mentioned processes bywhich it is possible to secure the elimination from heavler petroleun'l distillates of substantially all the phytocidal impurities and the removal therefrom of the oxidizable components and other potential sources of phytocidal components, whether originally present 'in the distillate or produced therein during the process of purifying it. More specifically, I prefer to use one of the processes which proceeds directly to the production of stable phytonomic oil s by controlling the temperature and adjusting the intensity of the agent or agents used for eliminating phytocidal impuritiesuntil substantially no potential sources of phytocidal products repoisons. In other climates, where high temperatures and brilliant sunshine are prevalent, it is desirable to remove substantially all such potential sources of ph tocidal substance. However, I do not wish to confine myself to any of the particular operations or combination of operations above described, or to any precise quality of oil produced, as it is likely that one-or other process or product may be preferable according to the circumstances, and that further improvements in both process and product may be made.

hat I desire to secure by-Letters Patent 1. A substantially non-volatile viscous oil free from phytocidal ingredients characterized by the fact that it is when sub'ected to severe meteorological action of air, eat and light substantially stable against the formation of ingredients having phytocidal action.

2. A parasiticidal oil emulsion comprising substantially stable components of the lubricating stock fractions characterized by substantial freedom from unsaturated components of lubricating stock and by substantial freedom from components readily oxigizable by the weather elements air, light and eat.

3. A substantially free. from phytocidal ingredients characterized both by the substantial absence of phyto- 'cidal impurities and by the substantial absence of components adapted to produce phytocidal products during exposure to extremes of weather. v

4. A substantially non-volatile viscous oil free from phytocidal ingredients characterized both by the substantial absence of phytocidal impurities and by the substantial absence of components adapted to produce 3 non-volatile viscous oil.

phytocidal products during exposure to severe meteorological action of air, heat and light.

pounds, and similar phytocidal impurities characterized by the fact that it substantially resists oxidation at 100 C. for 240 hours, as herein described.

I 6. As a new article of manufacture, a parasiticidal oil emulsion. having a viscosity between sec. and 350 sec. Saybolt, specificgravity between .8000 and .9000, boiling point between 150 C. to 400 C. substantially free from unsaturated components and which, agitated with air at 100 C. for 284 hours, does not produce more than about 25% of substances removable by 1.84sp. g. sulphuric acid washin through ful ers earth.

7. A plant parasiticide comprising a substantiall non-volatile viscous oil free from phytoci a1 ingredients characterized by the fact that it is when subjected to severe meteorological action of air, heat and light A parasiticidal oil-spray comprising a petroleum fraction practically freed from unsaturated hydrocarbons, sulphur comwith caustic soda and filtration substantially stable against the'formation of ingredients having phytocidal action.

.8. A plant parasiticide comprising an oil which consists of substantiallyv stable components of the lubricating stock fractions characterized by substantial freedom from unsaturated components of lubricating stock and by substantial freedom from readilyoxidizable components. i

9. A plant parasiticide comprising a substantiall non-volatile viscous oil free from phytocidal ingredients characterized both b the substantial absence of phytocidal impurities and by the substantial absence of components adapted to produce phytocidal products during exposure to extremes of weather.

10. A plant parasiticide'com rising an oil which consists of a petroleum raction-practically freed from unsaturated hydrocarbons, sulphur compounds, and similar impurities characterized by the fact that it substantially resists oxidation at 100 C. for 240 hours as herein described. 

